Sol－Gel法制备γ－Al_2O_3膜及其分离H_2／N_2气体特性的研究

Study on ultrafiltration γ Al 2O 3 membrane obtained by Sol Gel techniques and its properties of gas separation

溶胶－凝胶法是制备无机膜的一种重要方法，利用这种方法可以合成孔径为几纳米、孔分布狭窄的多孔陶瓷复合膜。本研究以异丙醇铝为原料，采用Ｓｏｌ－Ｇｅｌ法在微滤级的基质陶瓷管上制备了无裂纹的超滤级γ－Ａｌ２Ｏ３膜。通过气体渗透法测定了平均孔径和孔径分布。结果表明，这种复合膜管平均孔径为１．７７ｎｍ，孔隙率为４０．３％。考察了溶胶性质对成膜结构的影响，比较了基质管与复合膜管的气体渗透性能，研究了进料氢浓度和总流量对透氢过程的影响。发现透氢率和渗透通量与涂膜次数成反比，而氢气的渗透选择性却大大提高了。

Sol Gel is an important method to compose inorganic membranes, by which a porous composite ceramic membrane is produced with a pore size of a few nanometers and a narrow poredistribution. In our work, an ultrafiltration γ Al 2O 3 membrane has been prepared on the basis of microfiltration grade ceramic tube by the Sol Gel method using aluminium isopropylate (C 9H 21 AlO 3) as starting material. The pore size distribution and mean pore size are evaluated through gas permeation. The results show that the compositemembrane tube has a mean diameter of 1.77nm. and a porosity of 40.3%. The influence of properties of colloidal solution on the film deposition structure has also been studied. The gas permeaties of supported and composited membranes are compared experimentally. The effect of hydrogen feed concentration and total feed flux are investigated as well. It is found that the number of dipping is inversely related to both the hydrogen permeability and permeating flux, but directly to the permselectivity.